check engine light

sorry left out truck has 5,788 miles on it

Yes, probably would have set a Mass Airflow Sensor code.

light now has gone off after putting cap back on, is there a code still stored or has it reset it self? i am takin it back to dealer on monday.

There is still a code,and will be there until either the battery gets disconnected,or so many starts.Can`t remember how many.The light coming on has nothing to do with the oil change.

ok thanks was wondering because after i put it back on, and after a few cycles it went off. thanks again for the info. the dealer is getting it first thing monday morning and the service manager is going to hear about it

You don't think that false air would have been drawn into the engine via the oil fill, bypassing the MAF sensor and triggering the light?

thats what i was wondering, i am NO mech. thats why i asked here, nevertheless the dealer is getting it in morning to check and get a ear full.

I was replying to snipped-for-privacy@webtv.net (Bill) since he is pretty convinced that leaving the oil fill cap off had nothing to do with the check engine light coming on.

here are the codes and what they found, is this a common thing on this truck? again truck is a 2004 gmc sierra 1599 4x4 w/5.3 P0171 P0174 P0300 also found PIP#3232A what are these codes? also they said cracked upper manifold. they said something it was plastic and air cooled, is this true? thanks for the advise and info

opsss meant 1500 NOT 1599 sorry for typo